This invention relates generally to ball retainers for ball bearings and, more particularly, to a one-piece ball bearing retainer with a crimped configuration providing ball retention.
Many types of prior art ball bearing retainers and cages have been used. One of the major types includes welded metal retainers where two halves are welded together. These welded two-piece retainers have fair wrap-around and conformity to the ball shape. Operating temperature is limited by the lubricant and not by the retainer. However, it is difficult to ensure 100 percent good welds with a welded two-piece retainer design.
Riveted two-piece metal retainers are similar to welded two-piece metal retainers except the two halves are riveted together rather than welded. That type retainer requires many small rivets that are difficult to insert. Visual inspection is more accurate than with welded retainers; however, poor riveting may occur. Similarly, mechanically interlocked retainers also require two halves and may be difficult to fasten together.
Spring finger-type retainers offer a one-piece design but are difficult to make with sufficient ball contacting surface or wrap-around. Spring finger-type retainers usually require special heat treating. Polymer retainers offer one-piece design and have good wrap-around and ball conformity. However, polymer retainers are generally limited to lower temperature and low strength applications.
One proposed metal retainer is formed as one-piece by fashioning a sheet metal ring into an undulatory form with open ball pockets spaced apart by U-shaped connecting portions. After balls are placed into the pockets, the U-shaped connecting portions are upset, causing the sides of the U-shaped connecting portions to spread and partially conform to the contour of the balls. However, that proposed design fails to provide sufficient ball retention without gripping the balls to tightly.
The foregoing illustrates limitations known to exist in present ball bearing retainers. Thus, it is apparent that it would be advantageous to provide an alternative directed to overcoming one or more of the limitations set forth above. Accordingly, a suitable alternative is provided including features more fully disclosed hereinafter.